Godwin's Law FAQ
We know Godwin's Law, yes? To remind: As a Usenet discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one - link
For fandom, due to our unique specialness, we have Jurisimprudence to tell us of our discussion laws.
Such as Snacky's Law. To remind: Whenever two (or more) groups of people are arguing, anywhere on the web* (usenet, mailing lists, message boards, blogs, etc.), inevitably, someone on one side of the argument (regardless of age or gender) will compare the group on the other side to "those bitchy girls who made everyone's life hell in high school." - link
Here's what I can't find.
The likelihood during any discussion anywhere that someone will compare the discussion issue to starving children/saving whales/environmental activism/global warfare as a reason that discussion is pointless/stupid, the OP is stupid/dramatic, the posters are shallow/vapid, or just to piss people off (fun!).
Law, people. Someone either needs to find it or name it already.
ETA: Randomly, other useful daily laws. Yes, I am reading at Jurisimprudence.
Kerianne's Law of Dramatic Irony - In an online debate, the first person to accuse his opponent of spending too much time on the Internet and/or invite his opponent to "turn off your computer and go outside" automatically loses the argument, and should be subsequently forced to turn off his own computer and go outside. - link
Bookworm's Corollary - The first person to calculate the amount of time elapsed between her posts and her opponent's replies, and conclude that her opponent has been sitting at his computer all day refreshing the page and therefore has no life, automatically loses the argument. - (same link)